Gageotetrins A–C, Noncytotoxic Antimicrobial Linear Lipopeptides from a Marine Bacterium Bacillus subtilis

Gageotetrins A–C (1–3), a unique class of linear lipopeptides, consisting of di- and tetrapeptides and a new fatty acid were isolated from a Marine Bacillus subtilis. The structures of 1–3 were assigned by spectroscopic data and their absolute stereochemistries were ascertained by chemical derivatization. Compounds 1–3 displayed good antimicrobial activities with MIC values of 0.01–0.06 μM. However, these compounds failed to register any cytotoxicity (GI50 > 30 μg/ml) against human cancer cell lines.